The HR version of the fenix® 3 comes with an optical heart rate sensor integrated in the lid of the watch. This allows you to get around attaching a separate chest belt for the display of many functions.

The fenix® 3 HR is a GPS multisport watch, a smartwatch, an activity tracker and a navigation device in one.
Whatever your trip through nature looks like – you can see all interesting data on just one device on your wrist. Afterwards, you can comfortably analyse your performance with Garmin Connect™ (also available as an app for iOS and Android).

Heart rate sensor at the wrist
On the back of the device there is an optical heart rate sensor, which allows for a heart rate measurement without separate chest belt. You can thus not only monitor your heart rate during training, but also watch your daily activities and your calories burned.
For the measurement of physiological values, such as e.g. VO2max, lactate threshold, strain value above the heart rate variability, recovery and the running efficiency values, you still need the HRM™-Run heart rate chest belt.
Your heart rate cannot be determined during swim training in the water. To record the heart rate data in the water you need the optionally available HRM-TRI chest belt (item no. 2173717).